So it turns out I had a ton of carbon buildup on the intake valves – but also on top of the piston head inside the cylinders. My first time doing this so it took me a full day, but I'm happy with how the intake valves turned out.

For inside the cylinder, I did about 2 days soak with seafoam and rotating the crank a little bit every once in a while. The cylinders cleaned out a good but but there is still significant carbon buildup there. Honest question here – I've seen a lot of info on the walnut blasting or intake valves, but not much on why it you can't just walnut blast inside the cylinder as well? It wouldn't hurt the metal and you could vacuum out anything leftover. Or even put the piston top dead center and then do it maybe?


The car is an R55 turbo with 110k miles. I bought it at 90k and the guy told me "fill it with oil every week." I don't think it ever had any major work done to it, and maintenance before I bought it, I'm unsure of.

I noticed signs of an oil leak around the valve cover gasket (replacing that soon). The PCV hose and the whole hose area above the throttle bar was very oily and gunked up - something is leaking around there. PCV hose was so brittle it snapped in half when I was preparing to remove intake.

Unfortunately also have a head gasket leak as I have milky color in the oil cap, and I lose coolant (slowly). I'm hoping I can just fix it using a head gasket leak stopper for now



Some thoughts on the carbon cleaning :
- large compressor makes this a LOT easier. I used a 2gal tank that couldn't nearly keep up, and the whole process took me a lot of time waiting
- check out the intake manifold ports and throttle bottle, they are probably dirty as well and could use cleaning
- piston soak inside cylinders is helpful, but maybe you need a stronger solvent like acetone to really do good work. Also do it soon after warming the engine up to get a good hot soak. Still curious about people's thoughts on walnut blasting this area


Intake Valves before:


so much carbon that it absorbed a lot of the light - it was hard to see anything until after cleaning it a little

video:

Intake valves (process):


at least can see it now - but still more to clean

a little more

almost

good!

video:


(walnuts sticking to carbon residue):





I did make some scuff marks on the surface from the blaster wand hitting it. I hope this is okay




Inside Cylinders before:





video:



Insider Cylinders after seafoam soak:




still liquid left in this one





Inside intake manifold:

one of the intake manifold ports

video:

 

You got some build up, mine was pretty bad. I had to use the little scraping tools to get on the back side of the valve to nock off the carbon before I blasted it with out Bav Auto tools. Otherwise the walnut would just cake on the tar(carbon).

 

Yea this was happening to me (caking on) - the solution for me was increase the air pressure. It really started to come off at over 100 psi

 

Yep, i had so much the increase just made it pile up. The little tools did the first job. Then shoot it out with a blast of air only at 130psi. Valves closed of course.

https://www.ecstuning.com/b-schwaben.../008504sch01a/

 

That seems to be the trick - alternating between walnut blasting and doing the air only, keeping psi high

 

Thanks guys...great information.

 

Looks like some microscopic thing here